1. Field of the Invention
The present invention relates to a loading system and a traveling system for a magnetic recording/reproducing device. More particularly, the invention relates to an idler controlling apparatus in a magnetic recording/reproducing device, wherein the rotational force of a capstan motor transmitted to a travelling system in the device is selectively supplied to a supply reel and a take-up reel for controlling the travel of a magnetic tape.
2. Description of Prior Devices
Generally, magnetic recording/reproducing devices, which record and reproduce signals on and from a magnetic tape travelling along a predetermined path, include a drum and read/write heads on a deck, a tape transporting system for transferring the magnetic tape seated on a supply reel and a take-up reel along the predetermined path, a tape loading system for applying the magnetic tape tightly against the drum, and elements for driving the reels. Generally a magnetic recording/reproducing device includes a loading motor for driving the tape loading system and a capstan motor for driving the tape travelling system and the reels. The existence of two motors places limits on the minimization of the size and weight of the device.
A recent trend is to provide smaller and lighter magnetic recording/reproducing devices, such as those which use the widely available 8 mm tape cassette. One such small, lightweight device includes a tape cassette holder into which a tape cassette is inserted, a slider for moving the cassette holder horizontally backward and forward, and an upper chassis on which a rotary drum is installed. The holder, slider and upper chassis are located between an eject lever and a lower chassis. The holder is closed on the slider, and the magnetic tape from the cassette is first loaded onto the drum by the slider moving horizontally toward the drum. The drum thereby is placed wholly within the internal space of the tape cassette while the remainder of the loading operation takes place and remains within the internal space of the cassette during read/record operations. This results in a highly miniaturized tape recorder/reproducer. Examples of a cassette and tape recorder/reproducer of the latter type are described in WO 93/21631, published Oct. 28, 1993, and copending U.S. patent application Ser. No. 08/093,400, now U.S. Pat. No. 5,427,326 filed Aug. 4, 1993, assigned to the assignee herein, both of which are incorporated by reference herein.
A portion of such a device, to the extent relevant to the invention herein will be briefly described below with reference to FIG. 1, which illustrates a loading system and travelling system installed on a main (or lower) chassis 1 of a small/lightweight magnetic recording/reproducing apparatus, disclosed in Korean Patent Application No. 93-5016, which is incorporated herein by reference. The power provided by a capstan motor 2 is selectively supplied to the travelling system and the loading system to control both the running of the tape and the loading of the tape. The use of a single motor for both functions permits the deck to be small and light weight.
The capstan motor 2, which rotates in a forward or reverse direction in accordance with a mode control signal, is mounted on one side of the main chassis 1. A lever 3 is provided with an upper end anchored to a bracket that is attached to the chassis 1. The bracket is not shown in the drawing. A transmission gear 4, which rotates around a shaft 4a and is connected to the lower end of lever 3, meshes with gear 2a of the capstan motor 2. The gear 4 pivots to the right or the left under control of a plunger and in accordance with the rotational direction of the capstan motor 2 as disclosed in U.S. patent application Ser. No. 08/280,457, filed on the same date herewith, entitled "Power Transferring Device for Magnetic Recording and Reproducing Apparatus," and assigned to the assignee herein (corresponding to Korean Patent Application 93-14671 filed Jul. 30, 1993). When pivoted to the fight, the gear 4 transfers the rotational power of the capstan motor to gear 12, which is part of the tape travelling system. When pivoted to the left, the gear 4 transfers the power of capstan motor 2 to gear 5, which is part of the tape loading system.
The magnetic tape loading system includes gear 5, which is selectively in contact with gear 4, and a series of small gears 6 to 10. Gear 10 meshes with a ring gear 11, which operates in a well known manner to load the tape onto the rotary drum. The ring gear 11 is mounted on the main chassis 1.
The magnetic tape travelling system includes the second gear 12, which is selectively in contact with gear 4, a pulley 12a formed on second gear 12, a driven gear 13 and a belt 14. The driven gear 13 is brought into gearing contact with an idler gear 16 connected through the upper portion of a lever 15, so that the idler gear 16 swings to the right or to the left in accordance with the rotational direction of the capstan motor 2 to supply the rotational force to a supply reel or a take-up reel (not shown), respectively, installed on an upper chassis (not shown). The idler gear 16 is directly brought into gearing relationship with a gear (not shown) formed along the outer circumference of the supply reel, and the take-up reel is connected to a gear (not shown) along the outer circumference of the take-up reel via all auxiliary gear (not shown) to thereby transmit the rotational force of the capstan motor 2.
A cam gear 17 rotating around a shaft 17a is installed to mesh with the ring gear 11. A cam groove 17b is formed in the upper plane of the cam gear 17, and a pin 18b of a first lever 18 follows the cam groove. The first lever 18 pivots about a shaft 18a. The pin 18b projecting on the lower side of the first lever 18 fits into the cam groove 17b of the cam gear 17. A pin 18c at the lower end of the first lever 18 fits into the end of a second lever 19, which is installed in the transversal direction. The elements 17, 18, and 19 operate a switch (not shown) in the device to eject the upper chassis from the lower chassis.
In FIG. 1, the position of the transmission gear 4 for selectively supplying the rotational force of the capstan motor 2 to the magnetic tape loading system and travelling system is controlled by a plunger (not illustrated). In more detail, the gear teeth 4b of the transmission gear 4 are brought into gearing contact with the first gear 5 when gear 4 is pivoted to the left to transmit the rotational force of the capstan motor 2 to the loading system. The gear teeth 4c of the transmission gear 4 are brought into gearing contact with the second gear 12 when the gear 4 is pivoted to the right to transmit the rotational force of the capstan motor 2 to the travelling system.
When the gear 4 pivots to the right, bringing gear teeth 4c into gearing contact with the gear 12 to transfer the rotational force of the capstan motor 2 to the travelling system, the idler gear 16 swings to the right or to the left, depending on the direction of rotation of the pulley 12a, to bring the idler gear 16 into gearing contact with gears associated with the supply reel or take-up reel. In this case, the idler lever 15 swings right to left around the shaft 13a and the gear 13b is brought into gearing contact with the idler gear 16 to pivot the idler gear 16, but there is a problem caused by the fact that the idler lever 15 and idler gear 16 are free to move.
The problem is that the freely moving idler lever 15 and gear 16 may interfere with the proper seating of the upper chassis on the main (lower chassis). As seen in the references mentioned above, in a magnetic recording/reproducing apparatus of the type described, there is an upper chassis and a lower chassis, and the upper chassis has to be moved onto and seated properly on the lower chassis for proper loading and operation. A freely moving idler gear may inhibit accurate seating of the upper chassis by coming into contact with components on the upper chassis during the seating operation.